Hydraulic drive means for the weft inserting means in needle loom



Jun 4, 1968 M. DURAND 3,386,477

HYDRAULIC DRIVE MEANS FOR THE WEFT INSERTING MEANS IN NEEDLE LOOM Filed March 14, 1966 4 Sheets-Sheet 1 Fig-1 29 19 2o 22 n will 'lI/IIIIIIII M. DURAND 3,386,477 HYDRAULIC DRIVE MEANS FOR THE WEFT INSERTING June 4. 1968 MEANS IN NEEDLE LOOM Filed March 14. 1966 4 Sheets-Sheet t INVENTOR MARCEL DURAN D M. DU RAND 3,386,477 HYDRAULIC DRIVE MEANS FOR THE WEFT INSERTING June 4, 1968 MEANS IN NEEDLE LOOM 4 Sheets-Sheet 5 Filed March 14, 1966 June 4, 1968 M. DURAND 3,386,477

HYDRAULIC DRIVE MEANS FOR THE WEFT INSERTING MEANS IN NEEDLE LOOM Filed March 14, 1966 4 SheetsSheet 4 Fig.5

( L l l Fig.6

United States Patent 3,386,477 HYDRAULIC DRIVE MEANS FOR THE WEFT INSERTING MEANS IN NEEDLE 1.00M Marcel Durand, 26 Ave. Marechal-Leclerc, Grenoble, Isere, France Filed Mar. 14, 1966, Ser. No. 534,063 Claims priority, application France, Mar. 27, 1965, 10,997; Apr. 24, 1965, 14,562; Dec. 18, 1965,

6 Claims. (Cl. 139-122 ABSTRACT OF THE DISCLOSURE The present invention relates to shuttleless looms, that is to say, looms in which the shuttle is replaced by at least one needle which pulls the filling through the shed.

The three main operations in a loom are:

the insertion of the fillings into the shed; the beating up of the pick by the lay; the crossing of the warp threads by the darby.

In a complete cycle of the loom, each of these movements corresponds to a fraction of this cycle which depends on the type of loom, but this breakdown of the cycle is practically invariable in view of the mechanical coordination effected between the drives of the pick insertion member, the lay and the darby.

This mechanical connection has the fundamental drawback that the two other movements are affected by the variations in speed which may be necessary by the third movement.

It is known that there are no shuttle looms which can be universal, that is to say, capable of producing any fabric from any yarn. Accordingly, weaving plants, insofar as they are not narrowly specialized, must be equipped with a large number of different types of looms.

It has been proposed in the case of shuttle looms to replace the mechanical drive of the shuttle by a hydraulic drive, but these proposals were directed solely at improving the drive itself without ever having been directed at increasing the multiplicity of uses of the loom and a fortiori without being directed at achieving universality of the loom. Furthermore, these proposals, as far as known to the present inventor, never were actually reduced to industrial practice.

When the needle looms made an appearance, only mechanical drives for the needle were proposed due to a preconceived notion attributable to the failures encountered in shuttle looms upon attempts to use hydraulic drives or else because certain drawbacks have been found in hydraulic drives for this particular operation without it having been possible to overcome them.

The loom in accordance with the present invention is characterized by the fact that at least the movement of the needle is controlled by a hydraulic servomotor.

No one seems to have noticed that in the case of the needle loom, in opposition to what is possible in the case of the shuttle loom, a hydraulic drive makes it possible to tend towards the universality of the loom, this for, inter alia, the following reasons:

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The nature of the woven thread, which accounts predominantly for the volume and the weight of the shuttle and, therefore, for the drive of the latter, is practically without effect on the needle itself and, therefore, on its drive system.

Furthermore, it is practically impossible instantaneously to adapt the stroke of the shuttle to the nature of the work while the stroke of a hydraulic servomotor can be easily modified and, if necessary, subjected to programming. One can, therefore, not only change easily from one width to another of the Work, but one is also freed of the obligation of having a large number of shuttles for fabrics of other than plain texture.

Mechanically driven needle looms have constituted a certain advance over shuttle looms by making it possible to increase to a certain extent the multiplicity of use of the loom without however achieving universality. By way of example, it may be mentioned that in looms having two mechanically driven needles which exchange the filling at the middle of the shed, the stroke cannot be changed Without extensive modifications, which cannot be thought of in the course of ordinary manufacture.

In looms with a single mechanically driven needle, any reduction in the stroke of the needle is substantially symmetrical With respect to the axis of the fabric, which makes it necessary to displace the filling engagement point and which results in a complicating of the filling selection means and of the related thread clamping and cutting means. Furthermore, the duration of the stroke is related to the duration of the cycle so that a decrease in the stroke results in:

either a decrease in output it the duration of the cycle remains the same or in an increase in the fatigue of the equipment and of warp ends or filling if the time of the total cycle is reduced.

The primary object of the invention is to provide a fluid operated mechanism connected to the needle of the loom to impart a reciprocating movement to said needle and a control valve main operatively connected to energy storage means imparting a snap action to said valve means in both directions of movement.

In accordance with a development of the present invention, the hydraulic servo-motor for the control of the needle comprises adjustable means such as a stop which make it possible to vary the length of the stroke of the needle without displacing the point of engagement of the filling by the needle. This measure makes it possible to overcome the said drawbacks. This possibility of reducing the stroke of the needle by a simple stop in the servomotor makes it possible to obtain a large range of widths of fabrics on a single type of loom without loss of output or fatigue of the material, it being possible for the absolute speeds of the lay and of the darby to remain constant despite the increase in the number of picks per minute obtained automatically by the reduction of the time of the back and forth travel of the needle.

In accordance with another development of the invention, means are provided to vary the pressure of the driving fluid of the servo-motor within a complete cycle of the movement of the needle. It is thus possible to use weak fillings at high accelerations by reducing the value of the latter by decreasing the pressure of the motor fluid during the return movement of the needle. This change can take place without any repercussion on the other elements of the cyclemaximum speed of the needle, speed of the lay or of the darby.

The use of a hydraulic servo-control for the needle is dependent in current practice on the solution of five auxiliary problems which have been simultaneously solved by the present invention, namely:

First of all, in order to achieve the maximum output, it is advisable to reduce to a minimum the response time of the hydraulic control and for this purpose, in accordance with the invention, the hydraulic servo-motor is com trolled by a snap-action distributor valve, either that it is calculated or piloted in a manner known per se so that any intermediate position between the operating positions is a position of unstable equilibrium or, in accordance with a special feature of the invention, the control device of the distributor valve comprises an energy storage device, means for suddenly liberating the energy stored in the storage device at predetermined moments and means for recocking the energy storage device. Thus, the distributor valve operates in response to the liberation of this energy and this liberation can advantageously be brought about, in accordance with a feature of the invention, by the use of electromagnetic interlock devices such as electromagnets or equivalent electric motors, for instance torque motors.

Secondly, the movements of the main moving parts of the loom should be coordinated in a simple manner. It has already been proposed to control the lay and the darby hydraulically.

In accordance with a feature of the invention, the movements of the lay and of the darby are controlled by hydraulic servo-motors which, in their turn, are controlled by snap-action distributor valves actuated by energy storage devices comprising electromechanical interlocking devices such as electromagnets or torque motors and an electric or electronic programming device exciting the different electromechanical interlocking devices. The hydraulic control of the lay and of the movement of the frames further increases the universal nature of the loom and considerably simplifies the coordination between the three movements. This generalizing of the hydraulic control over the shuttleless loom made possible by the present invention has the advantage of making the loom practically silent, which is a problem which cannot be solved with the shuttle loom and can only be partially solved in the mechanically driven shuttleless loom.

Third of all, it should be noted that the introduction of hydraulics into the control of the movements and primarily the control of the needle introduces uncertainty as to the exact duration of the maneuver which is not present in mechanical controls.

In order to overcome this uncertainty, one could obviously merely link up the sequences, only with a substantial margin of safety as to the maximum time of each maneuver, but this would be to the detriment of the output.

In accordance with the invention, one or more of the hydraulically controlled members can be provided with an end-of-stroke detection device capable of preventing the starting of the immediately subsequent sequence.

Fourthly, the invention makes it possible to abandon purely mechanical programming for the balance of the installation, that is to say, for the sequential control of the elements which intervene in the total cycle of the loom. In accordance with the invention, the electric or electronic programming device also controls electromechanical devices intended to control directly, without hydraulic mediation and via energy-storing devices, moving parts other than the needle, the lay and the darby, such as the filling selector, the filling engagement clamp, the filling cutting device, etc. This additional control is considerably facilitated if, in accordance with the invention, the electromechanical devices intended to control members other than the needle, the lay and the darby, comprise electromechanical interlock devices capable of suddenly liberating the energy stored in the energy storage devices. This control requires for the starting of an operation only an electric pulse of small intensity and short duration, the work being supplied by the energy storage device.

In the arrangements proposed previously, the distributor valve slides or the mechanical members always are driven directly without the intervention of energy storing devices by electromagnets which have to supply the entire work. This results in high intensities and response times which are incompatible, in electrical or electronic programs, with a high output.

The present invention, therefore, makes it possible to abandon mechanical programming for the carrying out of the conventional cycle of the loom and to adopt electrical or electronic programming with the well-known advantages of this type of programming.

Fifthly, it is advisable to stop the needle immediately after it emerges from the shed. In certain known mechanical arrangements, the needle continues its retracting movement during the closing of the lay, which makes it necessary to slacken the filling at a still higher speed. In other embodiments, this stopping is obtained by cams which are difiicult to adapt to the width of the fabric. The drive device for the hydraulic servo-motor of the needle in accordance with the invention makes it possible to assure the temporary holding fast of the needle when it has let the shed so as to permit the movement of the lay.

As a result of the electrical or electronic programming, great benefit can be derived from this last-mentioned arrangement. Customarily, the filling thread is released by the clamp immediately upon its emergence from the shed and this is necessary when the needle still continues its movement outside the shed. By releasing this thread at a speed which is still high, as a result of the elasticity of the thread, it has a tendency to Whip in the open shed, which results in defects in the fabric after the beating up of the pick.

In accordance with the present invention, the programming device is so arranged as to cause the release of the filling thread by the needle when the latter has stopped outside the shed. With certain very elastic threads, this avoids the shrinkage of the pick within the shed.

A few examples of the invention will now be described by way of illustration and not of limitation, with reference to the accompanying drawing, in which:

FIGURE 1 is a schematic elevation of a needle control device in accordance with the invention;

FIGURE 2 shows schematically a variant of the needle control device;

FIGURE 3 shows diagrammatically still another variant of the automatic control device;

FIGURE 4 shows, on a larger scale, details of the drive of FIGURE 3, shown schematically and partially in section;

FIGURE 5 shows, on a larger scale, the detail represented in the frame of FIGURE 3 which concerns the clamp and its drive device on the end of the needle, the front side plate of the clamp having been removed;

FIGURE 6 is a fragmentary plan view of the device of FIGURE 5;

FIGURE 7 shows, in cross-section, the clamping device of the clamp;

FIGURE 8 illustrates the recocking of the clamp; and

FIGURE 9 shows details of the drive mechanism of FIGURE 3.

FIGURE 1 shows an embodiment of the invention in which the servo-motor controlling the needle is of the rotary type, with an idle period at the end of one of the strokes, corresponding to the emergence of the needle from the shed.

An arm or lever 10 is driven by a rotary motor 11 arranged at the end of the rotating shaft 12.

The servo-motor 11 mounted on the loom frame member comprises a stationary housing 13 comprising a toric recess 14. Within this recess 14 moves a sector 15 rigidly connected with the rotating shaft 12 mounted on the loom frame 150. This sector 15 in its movement strikes alternately against the two end walls of the toric recess 14, which correspond to the strokes necessary for the movement of the lever 10.

In FIGURE 1, the sector 15 is shown in its central position. On both sides of the sector 15 there are then two chambers designated 16 and 17 respectively.

The distribution system mounted on the loom frame 150 comprises:

an oil tank 18,

a pump 19 with its safety valve 20,

a distributor valve 21 having a displaceable valve member 22, which can be actuated by a cam 23 keyed on a shaft 23, the movement of which is strictly synchronized with the other moving parts of the loo-m (this valve member 22 is shown in a neutral position).

If the cam shaft 23 turns in the direction indicated by the arrow, the displacement of valve member 22 causes the chamber 17 to be connected with the pressurized input fluid and the chamber 16 with the tank. Accordingly, the sector 15 causes the rotation of the lever in the direction which corresponds to the emergence of the needle from the shed, the speed of operating being adjusted by a diaphragm 28. At the rear end of the stroke, the sector remains stationary while the circular position of the cam 23 does not cause any movement of the valve member and the sector. This time of stoppage is adjusted to permit the beating up of the pick by the lay, the fillingholder rod being at this time outside the shed.

When the shaft 23 continues to turn, the valve member 22 resumes its movement in the opposite direction, after having passed through the neutral position and causes the chamber 17 to communicate with the tank and the chamber 16 with the pressurized fluid. Accordingly, the sector 15 causes, during the stroke, the rotation of the lever 10 in the direction which corresponds to the insertion of the needle into the shed the speed of operation being adjusted by a diaphragm 31. At the end of this stroke, the cam 23' again causes the displacement of the valve member 22 which causes the return of the needle in a rearward direction and then the cycle continues as above. The feeding of the yarn has been diagrammatically represented at 152 and 153.

In this example, the programming is assured mechanically by the cam shaft 23 rotatably mounted in the loom frame 150, the movements of said shaft being derived from the operative movements of the loom. This arrangement does not make it possible to reach high speeds of the needle and imposes a certain uncertainty with respect to the movements of the needle. With an electric or electronic programming device, the cam 23' would be replaced by an electromechanical device such as a torque motor or one or two electromagnets of the snap-action type, as will be explained with reference to FIGURES 3 and 4.

In the embodiment shown in FIGURE 2, a direct drive of the needle is shown.

It is already known, as a matter of fact, to wind a flexible metal or plastic blade bearing the clamp on a drum. An alternating movement imparted to this drum results in the unwinding of the blade and therefore its passage through the shed, the subsequent winding onto the drum causing the emergence of the blade from the shed. The major difficulty of this solution consisted in the alternate driving of this drum which necessarily required for the large strokes gear or rack systems, noisy devices which poorly withstand the reversals in direction of operation and which make the lubrication ineffective.

In a loom comprising a flexible clamp-holder member wound on a drum, the drum may be driven at its center of rotation by a hydraulic servo-motor, and preferably according to the invention by a rotary hydraulic servomotor arranged concentrically with respect to said drum. It is sufiicient to distribute the oil alternately on one face or the other of the piston of the servo-motor to produce the alternate rotation of the drum and the reciprocation of the clamp.

The main advantages of this solution are:

The elimination of all gears or other mechanical parts subject to wear resulting in very great flexibility and silent operation,

The reduction of the inertia of the moving parts since only the drum and the moving sector of the toric servomotor remain,

The moving sector and the stationary part take up only a very small portion of the complete torus, so that one can very readily obtain a stroke of more than 300, which makes it possible to reduce the size of the drum to a minimum which is still acceptable in order to cause the clamp to pass through the entire shed in fabrics of current 'width,

The use of the hydraulic control makes it possible also to stop the stroke of the flexible clamp-holder blade at the moment when the clamp fastened at its end has entirely emerged from the shed. At this time, the lay can cause the clamping of the pick and return to its rearward position of rest. The clamp can enter the shed from this moment by driving the drum in the unwinding direction. It should therefore be noted that with this hydraulic control one eliminates the dead forward and return stroke of certain mechanical drum controls during the period of time necessary for the forward and rearward movement of the lay,

The inertia of the moving parts being reduced to a minimum, it is very easy to bring about the stopping without the intervention of the customary disengagements in specific positions of the different parts. Furthermore, starting is practically instantaneous with this minimum inertia, the oil pressure being still available.

In FIGURE 2, a needle 33 is borne by a flexible blade 34 wound on a drum 35. The drum 35 is keyed on a shaft 36 rotatably mounted on the loom frame 151 on which is fastened the rotary sector 37 of a hydraulic toric servo-motor 38. Two pipes 39 and 40 pass through the stationary sector 41 to connect the servo-motor with a distributor valve as shown in FIGURE 1.

It will be readily understood that it is suflicient to admit liquid under pressure into the pipe 39 and to place the pipe 40 in communication with the tank in order to cause the introduction of the needle 33 into the shed, the placing of the pipe 3? in communication with the tank and the placing of liquid under pressure in the pipe 40 to cause the movement in the opposite direction.

The arrangement of FIGURE 2 relates to looms in which there is only a single needle inserted through the entire shed. However, of course, control by the hydraulic servo-motor can also be applied to looms having a transfer system in which two symmetrical needles each pass through one-half of the shed, whether these needles are driven by a flexible blade or by a rigid rod in accordance with the known kinematic systems.

FIGURES 3 and 4 show a hydraulic servo-control having a hydraulic jack of the type having a cylinder and a piston the stroke of which is adjustable and which is controlled by a distribution valve, the displaceable valve member of which is subjected according to a main feature of the invention to the action of energy storage devices, the liberation of the energy being brought about by electromagnets controlled by an electric or electronic programming device which is known per se and will therefore not be described in detail. 1

FIGURE 4 shows details of FIGURE 3 on a larger scale. The interrelation of these figures is facilitated by the fact that they have in common the oscallating arm 85 and the servo-motor 59. f

In FIGURE 3, a gripping clamp terminates the lefthand end of a horizontal tubular rigid needle 51. This needle, which constitutes the filling insertion member, can pass through the entire shed and the clamp, which is at the lefthand end of its stroke (see position 50 shown in dashed lines), can take up a filling thread at zero speed. This thread, the reserve of which, as shown diagrammatically at 152 and 153, is located on the lefthand side of the loom frame 154, is distributed by any suitable known device (not shown) which can select from among several fillings depending on the weave of the fabric to be woven.

The needle 51 returns to the rear pulling the filling thread through the entire shed and the clamp releases it upon emerging from said shed (position shown in solid lines).

The needle 51 passes through a guide 52 located on loom frame outside the shed. The end thereof opposite the clamp is pivoted at 53 on the end of a half-arm 54 which itself is pivoted at 55, at its opposite end, on a driving half-arm 56. A driving arm 56 oscillates about a fixed pin 57 fixedly mounted on the loom frame 154 and is connected by an articulation 58 near its center of rotation with the piston shaft 67 of a linear hydraulic servomotor 59. The body of the servo-motor 59 is rigidly mounted on the frame 154 of the loom.

The arm 56 has the same length as the arm 54. The pivot 53 moves along a straight line passing through the axis of the guide 52 and the center of the pin 57.

A fixed pulley 60 of diameter D is fixedly mounted on loom frame 154 coaxially with the pin 57, while on the arm 54, coaxially with the pivot 55, there is mounted a pulley 61 fixedly mounted on said arm and having the diameter D/2. The two pulleys 60 and 61 as is already known, may be connected by a chain so as not to have any slippage between the two pulleys.

The angle of oscillation of the arm 56 is preferably selected less than 90 so that the angle of rotation of the arm 54 will be less than 180 in relative value with respect to the arm 56. It results from this that the conventional chain may be replaced by a metal blade or strap 62, the two ends of which are fastened by a fixed tensioning device to an apex 63 fixedly mounted on frame 154 and in the vicinity of the pulley 60. The central point of the strap 62 is fastened on the circumference of the pulley 61 at 64. The fixed points, the tensioning device and the blade or strap thus by their combination make it possible to function without play and without rubbing thus not requiring any maintenance. During the pivoting movement of the arm 56, the pulley 60 being stationary, a part of the blade 62 unwinds from the pulley while the diametrically opposite part (with respect to the pulley) winds onto the latter and vice-versa.

The linear servo-motor 59 thus imparts to the arm 56 the intermittent alternating movement adapted to the cycle of the shuttleless loom.

FIGURE 4 illustrates the principle of the distribution.

The servo-motor 59 is of the type including a differential piston 65, the face 66 of which facing the rod 67 of the piston is connected to a source of constant pressure (not shown) entering through port 68, the other face 69, of the piston, which is larger, being alternately placed in communication with the inlet 72 or the outlet 73 by the intermediary of a pipe 70 and by means of the distributor valve 71.

If the pipe 70 is connected with the inlet 72 at a pressure equal to that admitted at 68, the surface 69 being larger than the surface 66, the force exerted on the piston 64 is greater on the side '69 and the piston moves towards the left with respect to the figure. If the pipe 70 is connected with the outlet 73, the pressure acts only on the face 66 and the piston moves toward the right in the figure.

In this particular application of hydraulic devices which are known per se, it is possible to satisfy the following conditions:

(1) Rapidity of response to the distributor,

(2) Action of the servo-motor at a very specific moment.

As a matter of fact, for the forward and return operating times, one has only fractions of a second and the displaceable valve member of the distributor valve, which, in order to reach its full efiiciency, must have the smallest stroke possible, must operate suddenly within times which amount to a few milliseconds. It is known that these response times can be obtained by the action of springs under tension which constitute energy storage devices.

This operation must be carried at a very precise moment since it cannot be effected before the end of the preceding operation.

The sequential cycle of the loom determined by the programming device must, as a matter of fact, be as follows:

The lay having returned to its rear position of rest, it permits the giving of the order to the needle to enter the shed;

An end-of-forward-stroke detector of the needle permits the closing of the clamp and then the cutting of the filling of the preceding pick;

It is only after these two operations carried out at Zero speed of the needle that the order is given the latter to return rearward;

At the end of the return stroke, the clamp can release the filing and the lay is by this end-of-stroke caused to beat up the pick.

In order to achieve these objectives, the valve member 74 of the distributor valve 71 is placed under the control of two mechanical catches controlled by electromagnets.

A bell crank lever 75 pivoting about a fixed pivot 76 of the loom frame bears on the extremity of the valve member 74 and when engaged by an articulated armature or blade 77, pivots about a fixed point 78, and associated with an electric magnet 90 holds said valve member pushed towards the left in the figure against the force exerted by a compression spring 79, placing the servo-motor in communication with the pressure inlet.

A lever 80 pivoted at a fixed point 81 can be engaged by an armature or blade 82 pivoted on a fixed point 83 for maintaining the spring 84 under tension, the force of which is greater than that of the compressed spring 79.

This lever 80 is brought into the hooked position represented by a control arm 85 pivoted at a fixed point 86 which carries out a rapid movement from position A to position B with immediate return to position A. This ro tation is obtained mechanically or electrically from the movement itself of the needle drive, as represented diagrammatically in FIGURE 3.

The blade 82 is associated with an electromagnet 87 and is pulled back by a spring 88 against a stop 89. The blade 77 is associated with an electromagnet 90 and it is urged by a spring 91 towards the stop 92. The coils 87 and 90 are inserted in circuits shown in FIGURE 3, the operation of which will be made clear subsequently.

The stroke of the piston 65 is adjustable by means of a stop 93 which can be adjusted by means of its threaded rod 94 which is screwed into the end wall of the servomotor 59.

This device operates in the following manner:

Let us assume that at the start the different parts are in the position shown in FIGURE 4. The levers '80 and 75 are then held or hooked in position by their respective blades 82 and 77. The valve member 74 is all the way to the left, the servo-motor 59 is connected with the inlet and the piston 65 is about to move to the left until it comes into contact with the rod side end wall of the cylinder. The needle 51 is then at the end of its forward stroke in the shed and the clamp can grip the filling. An end-of-forward stroke detector of the needle closes the contact and energizes the coil 90. The blade 77 is attracted and the lever 75 is freed and swings in clockwise direction and the valve member 74 is pushed back towards the right by the spring 79 and connects the servomotor 59 with the outlet 73, thus causing the needle to emerge from the shed. The piston 65 of the servo-motor 59 at the end of its stroke will strike against the adjustable stop 93. This stroke is adjustable by displacement of the stop 93 depending on the width of the fabric. The

needle will remain in the emerged position during the forward and return motion of the lay 156, shown in FIG- URE 9, and the crossing of the warp threads. An end-ofreturn stroke contact 157, actuated by the lay, closes and energizes the coil '87 which attracts the blade 82 and frees the lever 80 which in its turn, under the action of its spring 84, moves the valve member towards the left in the figure, by pressing against the lever 75.

In this position, the valve member 74 sends the pressure into the servo-motor and causes the insertion of the needle into the shed.

During this last operation, the operative movement of the needle actuates the arm 85 and the recocking of the lever 80, thus affording the lever 75 the possibility of being subsequently released to start the cycle all over again.

It will be seen that by this arrangement it is very easy to rapidly control the valve member 74, the masses in volved being only a few grams, and the electromagnets having only to supply the unhooking force so that they may be very small. The only power which is somewhat more substantial is the power for recocking within a time which is far greater than the response time of the liberation.

Likewise, the position or shape of the servo-motor can be changed for instance by replacing the jack 59 by a toric servo-motor such as those described in the foregoing examples.

In certain cases, means (not shown) which make it possible to vary the drive pressure of the needle will be provided. This makes it possible to decrease the drive pressure and therefore the speed during the return stroke of the needle, the filling threads being then subjected to gentler treatment. The adjustment of this pressure will be effected in a suitable manner by the programming device which will also determine the movements of the lay and of the darby, if these are also moved in a manner known per se by hydraulic servo-motors. These hydraulic controls of the lay and of the dar-by will, in accordance with the invention, preferably be established in a manner similar to that of the drive of the needle, that is to say, they will comprise drive distributing valves for the servomotors of snap action which are under the control of energy storage devices the energy of which can be freed by means of electromechanical interlock devices, which are controlled by the programming device. I

In accordance with the invention, the programming device will preferably also control other electromechanical devices which, in their turn, via energy storing devices, control moving parts of the loom other than the needle, the lay and the darby, such as the filling grasping clamp, the filling selector and the filling cutting device.

An electromechanical control of the clamp in accordance with the invention is shown in FIGURES to 8, FIGURE 5 being an enlarged scale representation of the device shown within the frame 50 of FIGURE 3. It will be noted that purely mechanical programming is impossible to obtain due to the lack of precision introduced by by the cams, etc. in the sequences which last only for a few milliseconds.

The movable jaw of the clamp consists of a lever 110 articulated on a pin 111 which is fixed relatively to the body 112 of the clamp. One of the ends 113 of this lever serves to clamp the filling 114 in a U-shaped stationary jaw 115, as represented in FIGURE 7.

The lever 110 can, by means of a tooth 116, rest against an interlock blade 117 (FIGURE 5). The latter is articulated on a pin 118 fixed relatively to the body 112 of the clamp. A weak spring 120 brings the blade 117 against a stop 119 which is fixed relatively to the body 112.

The lever 110 is under the action of a tension spring 121, one end of which is attached to a fixed point 122 of the body. It is this spring which serves as an energy storage device which is proportioned to the force necessary for the clamping of the filling. On the lever 110, there is 10 fastened a lateral recocking finger 123 (FIGURE 6) wlhich passes through a hole 124 provided in the body 1 2.

The interlocking blade 117 can free the lever when its end of ferromagnetic material is attracted by an electromagnet 125 mounted on the loom frame at the outside of the shed in the vicinity of the emergence of the clamp which is guided furthermore by a stationary guide 126.

FIGURE 7 shows the end 113 of the lever 110 and of the fixed jaw 115 in cross-section. The end 113 has very slight play with respect to the inside of the U formed by the fixed jaw 115, which enables it to wedge the filling 114 against the inner edges of the U without shearing it (see position 113 in dot-dash lines in FIGURE 5).

FIGURE 8 shows cam 131 fixedly mounted on the loom frame 154 at the outside of the shed near the out let of the clamp in proximity of the guide 52 (FIG- URE 3).

Upon moving back with the clamp, the finger 123 successively occupies the positions a, b, c; at a, the finger has not yet contacted the cam 123 which it contacts only at b. At 0, the finger has had to rise on the inclined plane which has caused the release of the filling by the lever 110 and the cocking of the lever 110 behind the blade 117, the spring 121 'having been cocked while the finger 123 rises up the inclined plane.

The operation is as follows:

The clamp passes through the shed from right to left, the lever 110 is in the position represented in full lines, in which the clamp is opened and holds the springs 121 tensioned by resting against the blade 117.

The shape of the clamp body is such that in this movement of passage through the shed, the warp ends of the open shed which are perpendicular to the path of the clamp cannot be hooked. On the other hand, at the end of the passage through the shed, the filling, guided by a movable filling selection finger 132 actuated by the programming device, presents itself obliquely along the dotdash line 114a at a height such that it will be hooked by the nose 133 of the clamp at the end of the forward movement of the latter and will assume the position 1145.

At the end of forward stroke, at Zero speed of the clamp, the closing of contact (FIGURE 3) sends an electric pulse into the electromagnet 125, which is then opposite the blade 117 and attracts the latter by an amount which is very small but sufficient to free the lever 110. The latter, under the action of the tensioned spring 122, pivots in a counterclockwise direction and wedges the filling thread.

A few milliseconds after this closing, the order is given by the programming device to a knife (not shown) to cut the filling thread in the portion contained between the clamp and the preceding pick. Another order is then given by the programming device to bring about a return movement of the clamp.

The latter passes through the entire shed carrying the filling thread with it. Upon emergence from the thread, the finger 123 of the clamp then comes against the cam 131 which causes the opening of the clamp, the release of the filling thread and the cocking of the lever 110 against the blade 117.

The programming device then gives an order to beat up the pick to the lay and then the order to the clamp to pass again through the shed. In the clamp opening operation, the necessary force is supplied by the return movement of the clamp and is therefore not limited.

I claim:

1. In a loom having a needle adapted to be projected into and retracted from a shed to lay filling, in combination, a source of hydraulic pressure, hydraulic servo-motor means operatively connected to said needle to impart a reciprocating movement to said needle, hydraulic actuated valve means connected to operate said servo-motor means, energy storage means operatively connected to said valve means, means to periodically store mechanical energy di rectly derived from said source in said energy storage means, and electrically operated locking means to periodically lock said energy storage means in a stored energy condition and to suddenly liberate said stored energy in both directions of movement of said valve means in response to an electrical tripping signal.

2. A loom as set forth in claim 1 in which said valve means comprises a distributor valve having a movable member and in which said energy storage means comprises spring means acting upon the movable member of said distributor valve, said locking means comprising an electromagnet adapted to lock mechanically said movable member.

3. A loom as set forth in claim 1 in which said means to periodically store energy in said energy means further comprises second energy storage means and means to periodically store energy in said second energy storage means, and second electrically operated locking means adapted to lock said second energy storage means in a stored energy condition and to suddenly liberate said stored energy in said second energy storage means in response to an electrical tripping signal to store energy in said first-named energy storage means.

4. A loom as set forth in claim 3 in which said means to periodically store energy in said second energy storage means comprises continuously moving reset means operated in response to the motion of the loom.

5. A loom as set forth in claim 1 further comprising a hydraulically operated and electrically tripped beating-up mechanism, means to sequentially control said mechanism, and means to check the completion of the retracting movement of said needle and to authorize, after said completion, the emission of an electrical signal tripping the movement of said beating-up mechanism.

6. A loom as set forth in claim 1, in which said servo motor comprises a movable piston, a needle operating linkage operated by said servo-motor and operatively connected between said piston and said needle, and adjustable stop means for said piston to adjustably define the stroke of said needle.

' References Cited UNITED STATES PATENTS 1,847,584 3/1932 Winters 139-127 2,396,815 3/1946 Blum 251-70 2,712,429 7/ 1955 Ray 25174 2,723,681 11/1955 Glashan et a1 137-625.65 2,817,359 12/1957 Hayer 139-62565 2,865,404 12/1958 Mascrenhas 139-144 2,935,046 5/1960 Panissidi 137-62565 HENRY S. JAUDON, Primary Examiner. 

